Quantification of temporal lobe resections: a new approach

ABSTRACT

Extent of resection in temporal lobectomy has been traditionally based on intraoperative linear measurements. The complex geometrical contour of the temporal lobe limits the precision and accuracy of such measurements, and it is often difficult to verify the extent of actual resection after surgery. The authors propose a new method of evaluating extent of resection based on a 20-compartment model of the temporal lobe. The temporal lobe is divided into five anteroposterior coronal sections in relation to the anterior and posterior borders of the mesencephalon. Each section is then divided into superior lateral, inferior lateral, basal, and medial quadrants. The resulting compartments are easily identified on postoperative magnetic resonance images obtained along the coronal plane. Resection within each compartment is noted as none (0), partial (1), or complete (2). An index of resection can then be computed for superior lateral, inferior lateral, basal, and medial quadrants and for the whole temporal lobe. Potentially, this technique can be used to evaluate surgical failures and correlate extent of resection with surgical outcome and neurologic complications. It also allows objective and semiquantitative comparison of surgical approaches practiced at different institutions.